Hydraulic pump apparatus



Sept-Z8, 1954 J. s. ROBERTS HYDRAULIC PUMP APPARATUS 4 Sheets-Sheet 1 Filed Jan. 13 1951 Jack J. Roberzs INVENTOR.

ATTORNEYJ J. S. ROBERTS HYDRAULIC PUMP APPARATUS Sept. 28, 1954 4 Sheets-Sheet 2 Filed Jan. 13 1951 A TTORNEYJ Sept. 28, 1954 J. 5. ROBERTS HYDRAULIC PUMP APPARATUS Fild Jan. 15, 1951 4 Sheets-Sheet 3 i Wm R N mm m om M, R 7p A J. 5 k

Sept. 28, 1954 J. 5. ROBERTS HYDRAULIC PUMP APPARATUS 4- Sheets-Sheet 4 Filed Jan. 13 1951 z/ac/r J. Robe/"fa INVENTOR= M 7 0 Patented Sept 28, 1954 UNITED STATES PATENT OFFICE HYDRAULIC PUMP APPARATUS Jack "S. Roberts, Houston, Tex.

Application January {13, 1951', Serial NO. 205,883

-9 Claims. 1

This invention relates to new and useful improvements in hydraulic pump apparatus.

One object of the invention is to provide :an improved hydraulic pump apparatus which is particularly adapted for use with well devices, such as well packers, cutting and fishing tools, liner pullers and the like, whereby said devices may be set and released or otherwise actuated by means of said apparatus.

An important object of the invention is to provide an improved hydraulic pump apparatus adapted to be combined with any suitable well tools and having means for-developing a desired hydraulic pressure which may be utilized to set, anchor-orotherwise operate the tool ina required manner; said apparatus also including means for selectively releasing said hydraulic pressure to efiect release of said well tool to permit its removal from the well bore after operations are completed.

Another object is to provide a hydraulic pump apparatus, which is adapted to be lowered within a well bore on a conductor, such as a well :pipe, and which is arranged to be-actu'ated to develop a hydraulic pressure by rotating the lowering conductor in one direction, with release of the hydraulic pressure being effected by a rotation of the conductor in an opposite direction, whereby the apparatus is under the-control of the operator-at thesurface.

A particular object is to provide'an apparatus, oithe-character described, which is so constructed that the hydraulic pressure may be developed or built up and then released any number of times without withdrawal of the apparatus from the well bore.

A further-object is to provide a hydraulic pump apparatus for use in well bore operations and having means for automatically and effectively limiting the hydraulic pressure'whichis generated or developed by the apparatus, whereby the possibility of damaging byexcessive pressure the well tools with which the apparatus is used is obviated.

Another object is to provide an apparatus, of the character described, having 'an improved hydraulically expansible slip mechanism which adapts the apparatus for use with a well packer, linerpuller or other types of which tools employing a gripping slip mechanism.

The construction designed to carryout the in-- vention will be hereinafter described together'with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown, and wherein:

Figure 1 is a view, partly in section land partly elevation of .a hydraulic pump apparatus, con-- structed accordance .with the invention,

Figure 2 is -a horizontal, cross-sectional view, taken on the line 2-;2 of Figure l,

Figure 3 is an enlarged elevation of the lower portion .of -:one of .the .pump cylinders illustrating the main control valve in ;a :closed :position,

Figure 4is an enlarged View Of the lower portion of :three of the pump cylinders, with one of said cylinders :being shown in section to illustrate the intake and main zcontrol'yalves,

Figure 5 is an enlarged, sectional view of the gripping-slip assembly,

Figure 6 .is a horizontal, cross-sectional view, taken on the line fi sfixof Figure 5., and

Figure 7 is a transverse vertical sectional View of the pumpapparatusiand gripping slip assembly incorporated in a well packerhaving hydraulically expansible packing elements.

Figure 8 is vertical-sectional View of a modified form of the apparatus, wherein a hydraulically actuated cutter device is illustrated in combination with :the hydraulic pump apparatus.

Figure 9 is a view similar to Figure l, and illustrates a modification in which the pump housing is rotatable with the :controltubing.

In the drawings, the numeral l0 designates a tubular housing or shell within which the improved hydraulic pump apparatus A is mounted. The apparatus is illustrated in Figure? as combined with-:a well packer-and insuch instance the upperre'nd of .the shell m is formed with a reduced portion 11 and a hydraulicallyexpandable packing sleeve :or element .12 surrounds this portion and has :its upper andlowerends suitably attached thereto. When pressure is introduced into the bore of the packing sleeveor element 12, said ele-' ment is expanded radially outwardly into-engagement With-the wall :of a well .pipeorcasing' [3.

The lower portionof the shell I0 has connection with a .gripp-ingxsleeve assembly B and below the gripping slip assembly is'a second packing element In which le -constructed in substantially the same manner as the upper packing element l2. The extreme lower end of the housing or shell, which for purposes of illustration is shown as a single integral piece but which would probably be made up of varioustubular sections, rests upon a bearing flange 14 which is secured to .a tubular mandrel or conductor 15. The {mandrel or conductor extends -.entirc y through :the shell andmay be connected with the usual well tubing (not shown). The shell 10 and its associate parts are confined against upward movement onthe conductoror mandrel 45 .by an upper bearing flange it which is also secured to the conductor. Suitable bearings ll, together with an type packing ring, may be interposed between the confining and supporting flanges M and It and the shell, whereby the conductor or mandrel i is freely rotatable with respect to said shell, but packed ofi elimihating possibility of fluid entering between mandrel and shell. With this arrangement, it is apparent that the mandrel may be utilized to lower the entire apparatus within the well bore and yet said mandrel may be rotated with respect to the shell. Since the mandrel or conductor i5 is tubular it is obvious that fluid may be pumped downwardly therethrough to perform various well operations.

The hydraulic pump apparatus is clearly shown in Figures 1 to 4 and said apparatus includes a fluid reservoir it which is formed within the shell or housing l0 between an upper closure plate 19 and a lower or bottom plate iii]. The plates l9 and 20 are circular in cross-section and are suitably secured to the shell by screws 2 I. The space between each partition forms the fluid reservoir 18 and each plate has a central opening 22 through which the tubular mandrel or conductor l5 extends. Suitable packing (not shown) packs oil between the mandrel and the partitions or plates l9 and 20. Upper plate l9 has a relief opening 59a which allows withdrawal of fluid by pump or pumps without creating a vacuum within the reservoir.

Disposed within the reservoir 18 and located preferably at spaced radial points therein is a plurality of hydraulic pump cylinders 23 (Figure 2). The pump cylinders are of identical construction and each cylinder has its upper end threaded. into an opening 24 (Figure 1) provided in the upper plate I9 of the reservoir. The lower end of each cylinder is threaded into a body or base element 7.5, which element extends through an opening 26 in the lower plate or bottom 20 of the reservoir. A suitable packing 21 seals ofi around each base element and the bottom plate 20.

Each cylinder is formed with an axial bore 28 and with an enlarged counter-bore 29 at its up per portion, whereby an internal shoulder 36) is formed within each cylinder. A piston 31 is adapted to reciprocate within the bore 28 of the cylinder and a piston rod or actuator 32 extends upwardly from the piston through the counterbore and projects upwardly through a guide collar 33 from the upper end of the cylinder which locates the upper end of said rod or actuator in a plane above the top plate [9 of the reservoir. Each piston is constantly urged toward an upper position within its cylinder by a coil spring 34 which is confined between the internal shoulder 30 in the cylinder and a transverse pin 35 which extends through said rod. The coil spring thus tends to maintain each piston in its uppermost position within the cylinder.

For imparting a reciprocating motion to the pistons 3| an annular split cam 36 is formed with an upstanding clamping collar 31, whereby the cam may be engaged about and secured to the mandrel or conductor 5. The under side of the cam is formed with a cam surface 38 and the upper end of each actuator or piston rod 32 is provided with a roller 39 which engages the cam surface. The contour of the cam surface 38 is such that upon a rotation of the mandrel or conductor which effects a rotation of the cam, the piston rods or actuators 32 of the various pistons are reciprocated within their respective cylinders. Since the coil spring 34 associated with each piston is urging the piston toward a raised position, the roller 39 of each piston rod or actuator is maintained in engagement with the cam surface; as the cam rotates the contour of the cam surface 38 depresses the piston rods 32 to accomplish the downward stroke of each piston. The coil spring 34 effects the upstroke of each piston.

The reservoir 18 which contains the hydraulic fluid has communication with the lower end of each piston through an intake port it which extends radially through the upper portion of the base element or block 25 of each cylinder (Figure 4) A spring-pressed intake valve 41 is disposed within a lateral passage 42 which communicates with the intake port ll! and the passage has communication beyond the valve 4! through an opening 43 with the lower end of the cylinder 23. Thus, upon the upstroke of each piston the intake valve 4| is opened and fluid is drawn from the reservoir through the intake port 46] and opening 43 into the lower end of the cylinder 23.

Upon the downstroke of the piston the fluid is forced outwardly through the passage 43 into the lateral passage 42 and past a spring-pressed back check valve i l mounted in the lateral passage. It is evident that the pressure developed upon the downstroke of the piston will close the intake valve Al. The fluid pumped downwardly from each cylinder, upon passing the back check valve i i, flows through an outlet bore or passage 45 which is provided in the element or body 25. An outlet line 46 has connection with the lower end of the passage 45 and, as will be explained, extends to the mechanism which it is desired to actuate.

It will be evident that upon each stroke of each piston said piston will draw fluid from the reservoir past the intake valve 4| and during such stroke the back check valve 44 will be seated. Upon the downstroke the fluid previously taken into the lower end of the cylinder will be forced outwardly therefrom from the lateral passage 52 and the outlet bore or passage 45 to the line (it, thereby building up a pressure in the line 46.

For controlling the operation so far as the hydraulic pressure which is developed in the outlet line 46 of each piston assembly is concerned, a master control valve ll is mounted within the base element or body 25. This valve is of the rotary type and has a transverse passage or opening 48 therein which is adapted to register with a short lateral passage 49 formed within the body 25. As is clearly shown in Figure 1, one end of the lateral passage 49 communicates with the outlet bore 35 while the other end of said passage communicates with an angular by-pass passage Efi. The upper end of the by-pass 59 communicates with the reservoir it while the lower end of said passage communicates with the lower portion of the outlet bore 35 below the lateral passage 49. A spring-pressed pressure relief valve 5| is mounted in the angular by-pass 5c and remains closed, until the pressure in the outlet bore 35 and outlet line 45 increases beyond a predetermined point. If the pressure in the bore 55 and line 46 exceeds a predetermined amount, then the valve 5! automatically opens to relieve the excessive pressure therein.

By referring to Figures 1 and 4-. it will be evident that when the main control valve 13' is in the position shown in Figure 1, operation of the piston associated with said main valve will build up a pressure in the line 46 for at this time communication between the outlet bore @5 and the by-pass passage 50 is shut ofi by the 5., main valve. The conductor or mandrel maycontinue to rotate to reciprocate the piston to continue to build up pressure in the line 46, and

such pressure builds up to a predetermined point in accordance with the adjustment of "the relief or safety valve 51. If the pressure in the line 46 exceeds the pressure for which the safety or relief valve is adjusted, this valve will open to relieve pressure in the line, and thus the valve 51 functions-to limit the pressure which may be built up in said line.

'When the main control valve 41 is rotated to align its transverse opening 48 with the lateral passage 49, a communication is -'established between the outlet bore 45 and the by-pass 5 0, and in such instance'operation of the piston '3-1' andprovided with a suitable clamping collar 53. A'plurality of spaced teeth or fingers 54 project upwardly from the operating element and coact with an actuating arm 55 which is preferably constructed of spring steel. The actuating arm 55 has one end secured to the projecting end of the control valve "body '41 and when the operating element is rotated in a direction to the right, the resilient actuating arm will merely ride on the upper surface of the teeth or fingers. In this position which is illustrated-in Figure 4, the opening 48 in the valve "41 is misaligned or in position closing the lateral passage -49 and therefore, when the mandrel or conductor is rotated in a direction to the right with respect to the housing It! and the pump units, the pistons of said pump units are reciprocated to build up a pressure in the outlet bore 45 and line 46. The rotation of the rotary type main valve '48 is limited by a limiting arm 56 which engages a stop pin 51 (Figure 3), said arm being secured to that side of the main valve which is opposite the resilient actuating arm 55.

'Upon a rotation in an opposite direction of the mandrel or flow conductor 15, which would be a left hand rotation, the resilient actuating arm 55 will engage between the fingers or teeth 54 of the operating element 52, wherebyfthe arm 55 is swung to impart a rotation to the main control valve 41. Rotation in this direction is limited by a second stop pin 58 which is engaged by the limiting arm 56 and this aligns theop'ening 48 through the valve with the lateral passage 49 to establish communication between the outlet bore 45 and the by-pass 50. It is'apparent that the limiting pins 51 and 58 and their coaction with the limiting arm 56 assures that proper rotation-of the valve is effected upon each operation. The main control valve "4 is preferably of" the tapered type and a coiled spring 59 which surrounds the reduced extended end of the valve member and which is confined betweenia shoulder 59a Yon said valve and the outer surface ''of the base or body 25 functions to hold the valve in lateral passage :59. I From the foregoing, :it will. be seen that a rotation of the mandrel \er' flow conductor 1195 to the right the main control valve 4 is automatically moved into the position shown in Fi ure 1 which allows the pistons to be actuated to build up a pressure in the outlet line 55. Upon a rotation to the lef-tthe'main valve 41 is moved to a position aligning its opening 4'8 with the lateral passage 49 toestablish-communication:between the outlet bore 15 and the byp'ass 5 0 with :such communication established, operation o'ffthe pistons will merely displace iluid from one area in the reservoir to another area in the reservoir, and no appreciable "pressure will be built up in the line 46.

In order to" maintain the outer shell or housing 10 stationary while the mandrel or conductor 15 is rotated to control operation of the hydraulic pump mechanism A, a plurality of friction :shoes60 are suitably mounted on the housing or shell Ill-(Figure "7). These 'iric'ti'on shoes contact the wall of the pipe or well casing within which the apparatus is lowered, and said shoes may be mounted in any desired position on the shell or housing. Also, the shoes could be replaced with the usual type of bowed ffriction springs.

The friction shoes have been illustrated as mounted immediately below a gripping slip assembly B, which assembly is adapted to be actuated "hydraulically by the pressure developed or built up in the pressure line 46. The gripping slip assembly is clearly shown in Figures =5 and 6 and includes an outer housing 61 which has been illustrated as a part of the shell or housing [0. The housing B! of the slip assembly is formed with diametrically opposed openings 62 and a gripping slip or element 153 is movable within each opening. Each gripping slip is generally arcuate in cross-section and the upper portion of its outer surface is provided with teeth 64 for locking against upward movement, while the lower portion of its outer surface is formed with gripping teeth 55 for locking against downward movement. The gripping slips or elements 63 are movable radially in a plane transversely of the axis of the housing and the slips are normally held in an inward or retracted position by means of coil springs 66 which connect the inner surfaces of the slips to each other. 'Inward movement of each slip is limited by shoulders 63a formed on the slips and adapted to engage the outer surface of the housing.

For moving the slips outwardly into a position inengagement with the 'well pipe, each slip is provided with a cylinder 61 which has its closed end formed with a pivot lug 68 (Figure 6). The lug 68 is engaged within a recess 69 formed in the inner surface of the slip'or gripping element and a pin 10 pivotally connects the cylinder to said slip.

A piston 1| is slidable within each cylinder 61 and each piston is pivotally connected by a pin 12 with the gripping element opposite to the gripping element to which its cylinder is connected. A fluid inlet port 13 communicates with the interior of each cylinder between the closed end of the cylinder andits piston, whereby pressure fluid .may be. conducted thereto. -The inlet ports 13 have connection through a vfluid c'onductor 14 which extends from the outlet line 45. Thus, when the hydraulic pump units are .actuated to :build up a pressure in the outlet line it, this pressure .is "conducted through the conductor 14 to the inlets 13 :of the piston and cylinder assemblies of the gripping slips. The application of pressure to the pistons H and cylinders 6'! results in a radially outward movement of the gripping elements, whereby said elements are engaged with the wall of the well pipe 13.

The conductor 14 which conducts pressure fluid to the gripping slip assembly is provided with an extension 14a which has communication with the lower packing element I2a and thusat the same time that pressure is conducted to the gripping slip assembly to actuate the same, the lower packing element is expanded. An upwardly extending conductor 141) has its lower end in communication with the pressure line 46 and the upper end of this conductor directs pressure fluid to the upper packing element [2. It will thus be obvious that when the hydraulic pump units are operated, pressure fluid is directed to the gripping slip assembly to expand the gripping slips into engagement with the well pipe I3 and at the same time, hydraulic fluid pressure is directed to the packing elements [2 and 12a to expand such elements.

From the foregoing, the operation of the complete apparatus when employed with a well packer is obvious. The assembly is lowered into the well pipe 13 on the lowering conductor and at such time it is desirable that the main control valve 4! is in a position with its opening 48 aligned with the lateral passage 49. In such position free by-pass of fluid through the system is possible and even though there might be a rotation of the conductor or mandrel 55 during lowering, there would be no operation of the pump units to build up an appreciable pressure in the pressure line 46 and the conductors '14, 74a and 14b extending to the gripping slips and packer elements.

When the position at which the packer is to be set is reached, it is only necessary to rotate the mandrel ii in a direction to the right, and when this occurs the coaction between the teeth 54 of the operating element 52 with the resilient actuating arm 55 will operate the main control valve 4'! and move it tothe position shown in Figure 1. In such position communication between the outlet bore 45 and pressure line 46 and the by-pass is shut ofi, so that continued rotation to the right will result in operation of the pistons 31 of the pump units. The outer shell or housing It is maintained stationary during rotation of the conductor or mandrel I5 by means of the friction shoes til. As the pump units operate to build up a pressure in the line 46 and also in the lines '54, 'Ma and 741), this pressure is applied to the cylinders E3? and piston H of the gripping slips to move the gripping slips radially outwardly into contact with the wall of the well pipe. At the same time pressure is applied to the expandible packer elements l2 and We to move them into sealing engagement with the well pipe. Due to the provision of the safety or relief valve 58, continued operation of the pump units after the slips are expanded and after the packing elements are insealing position cannot be excessive because upon the pressure reaching a predetermined point the check or relief valve 5| will open to lay-pass fluid through the passage 50 and back into the reservoir I8.

When it is desired to release the device it is only necessary to rotate the conductor or mandrel [5 in a reverse direction, which would be a left hand rotation. The coaction between the teeth 54 of the operating element 52 with the actuating arm will rotate the main valve to a' position establishing communication between the out let bore and the by-pass 5t, and this will relieve all pressure in the system since fluid from the conductors 14, 14a and 14b may iiow back into the reservoir.

It is pointed out that since the device can be readily set by rotation of the mandrel in one direction and released by rotation of the mandrel in an opposite direction, it is possible to set and release the device without removing the same from the well bore. Thus, if an initial setting of the apparatus is not satisfactory, it is only necessary to rotate the mandrel in a reverse direction which will release all hydraulic pressure and allow retraction of the packers and slip mechanism. The device may then be set at another elevation within the well bore.

Although the unit is illustrated as combined with a well packer, it is pointed out that the pump apparatus A may be combined with any desired type of well tool, such as a cutting or fishing tool, tubing anchor or a liner puller. The particular slip mechanism may also be utilized for purposes other than anchoring a well packer. In Figure 8, the pump apparatus A is shown as combined with a cutting tool D. This cutting tool D has cutter knives 8b which are connected to pistons 8|. Each piston Si is normally urged inwardly by a spring 82, but upon the admission of hydraulic fluid from line it, it is moved outwardly in the radial bore 83. The fluid in line 14 is supplied by the actuation of the pumps 23 of the unit A in the same manner as described above in connection with the operation of the gripping sleeve assembly B and the packing elements i2 and lid of Figure '7. The invention is not to be limited to any particular number of pump units, four of which have been shown, since it is obvious that more or less may be employed in accordance with the particular operations and well tools with which the device is combined. The invention is also not to be limited to activating the pumps by having them stationary with the shell and activating them by having the cam attached to the rotatable conductor tube or mandrel. Thus, in Figure 9, the pump apparatus A is shown with the cam ring 3604 secured to the shell It by screws or other suitable securing means. Also, the operating element 52a is fixed to the shell it! by screws or other suitable securing means. The plates 49a and 23a are connected to the mandrel is and the chamber ita is formed by a sleeve 50a which is integral with the plate 19a and 20a or is connected thereto to form a chamber housing for the chamber 18a. The rest of the structure of Figure 9 is substantially the same as the device of Figure 1.

In the operation of the device of Figure 9, rotation is imparted to the mandrel it as in Figure l, and the chamber housing defined by the plates [9a and 20a, and the sleeve We would rotate therewith. However, the cam ring 38a and the feeler element 52a would remain stationary with the shell H], which would be held fixed by the friction means or a similar device. Otherwise, the operation would be the same as in the structure of Figure 1.

With respect to the slip mechanism, it is pointed out that the gripping slips are arranged to lock against both up and down movement and also the slips move in a true radial plane. This makes it possible not only to provide a tighter gripping engagement with the pipe but also assures a positive disengagement or retraction of the slips when the pressure thereon is released.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

Having described the invention, I claim:

1. A hydraulic pump apparatus including, a housing having a fluid reservoir therein, a cylinder mounted within the housing and having communication with the fluid reservoir, whereby fluid from said reservoir may enter said cylinder, an outlet line extending from said reservoir, a piston reciprocable within the cylinder, a rotatable mandrel extending through the housing, coacting means on said mandrel and on the piston for reciprocating the piston upon a rotation of the mandrel with respect to the housing and piston, whereby a hydraulic fluid pressure is built up in the outlet line extending from the cylinder, and means disposed between the mandrel and housing and operable upon a reverse rotation of the mandrel with respect to the housing for directing the pressure fluid from the outlet line back to the reservoir to release the pressure in said line.

2. A hydraulic pump apparatus, including, a housing having a fluid reservoir therein, a cylinder mounted within the housing and having communication with the fluid reservoir, whereby fluid from said reservoir may enter said cylinder, an outlet line extending from said reservoir, a piston reciprocable within the cylinder, a rotatable mandrel extending through the housing, co-acting means on said mandrel and on the piston for reciprocating the piston upon a rotation of the mandrel with respect to the housing and piston, whereby a hydraulic fluid pressure is built up in the outlet line extending from the cylinder, safety valve means connected in the outlet line to maintain the pressure in said line below a predetermined limit, and means disposed between the mandrel and housing and operable upon a reverse rotation of the mandrel with respect to the housing for directing the pressure fluid from the outlet line to the reservoir to release the pressure in said line.

3. A hydraulic pump apparatus adapted to be lowered within a well bore and including, a housing having a hydraulic pump therein, an actuator for said pump projecting from the upper end of the pump, a mandrel extending axially through the housing and rotatably connected therewith, a hydraulic pressure line extending from the pump, means on the mandrel and co-acting with the pump actuator for operating said pump upon a rotation in one direction of the mandrel with respect to the housing to build up a pressure in the pressure line extending from said pump, and means actuated by a reverse rotation of the mandrel with respect to the housing for releasing the pressure in the pressure line, said last-named means being disposed between the mandrel and the housing.

4. A hydraulic pump apparatus as set forth in claim 3, together with a safety valve means connected in the pressure line and operable to relieve pressure in the line when the same exceeds a predetermined point to thereby maintain the pressure Within the line below a predetermined limit.

5. A hydraulic pump apparatus adapted to be lowered within a well bore and including, a

housing having a hydraulic pump therein, an

actuator for said pump projecting from the upper end of the pump, a mandrel extending axially through the housing and rotatably connected therewith, a hydraulic pressure line extending from the pump, means on the mandrel and coacting with the pump actuator for operating said pump upon a rotation in one direction of the mandrel with respect to the housing to build up a pressure in the pressure line extending from said pump, a main control valve associated with the pressure line adapted to be closed to permit pressure to be built up in said line and adapted to be opened to release pressure in the line, and means secured to the mandrel and coacting with the control valve for closing the valve when the mandrel is rotated in a direction to operate the pump and for opening said valve upon a rotation of the mandrel in a reverse direction.

6. A hydraulic pump apparatus as set forth in claim 5, together with a safety valve means connected in the pressure line and operable to relieve pressure in the line when the same exceeds a predetermined point to thereby maintain the pressure within the line below a predetermined limit.

'7. A hydraulic well tool including, a housing having a hydraulic pump therein, a hydraulically actuated gripping assembly below the housing and non-rotatably connected with the housing, a tubular conductor extending through the housing and assembly, means setting up a rotatable connection between the conductor on the one hand and the housing and gripping assembly on the other hand for rotatably supporting the assembly and housing on the conductor whereby said conductor may be rotated with respect to the housing and assembly, a pressure line connection extending within the interior of the housing and assembly and between the hydraulic pump and the gripping assembly whereby operation of the pump actuates said assembly, means for operating the pump to develop operating pressure in said pressure line upon a rotation of the conductor in one direction with respect to the H housing to thereby actuate the gripping assembly,

and means operable upon a reverse rotation of the conductor with respect to the housing for releasing the hydraulic pressure in the pressure line, said last-named means being disposed between the conductor and the housing.

8. A hydraulic well tool as set forth in claim 7, together with a safety valve means connected in the pressure line and automatically operable when the pressure exceeds a predetermined point for relieving pressure in the line to maintain the pressure in the line within predetermined limits.

9. A hydraulic well tool as set forth in claim '7, together with a hydraulically actuated well packer which is supported by the housing, and a second pressure line extending from the first pressure line to said packer, whereby said packer is actuated simultaneously with the gripping assembly.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,668,919 Lundstrom May 8, 1928 1,764,178 Loughead June 17, 1930 1,941,813 Nixon Jan. 2, 1934 2,171,171 Brauer Aug. 29, 1939 2,286,365 Lane June 16, 1942 2,436,797 Deschamps et al. Mar. 2, 1948 2,501,054 Huber Mar. 21, 1950 

